Regioselectivity in the Schmidt Reaction: First Synthesis of Pyrano[3,2-b]azepines
作者:Marijan Kočevar、Franc Pozgan、Slovenko Polanc
DOI:10.3987/com-01-s(k)53
日期:——
The Schmidt reaction of 5,6,7,8-tetrahydro-2H-1-benzopyran-2-ones (1) has been investigated. Derivatives of pyrano[3,2-c]azepines (2) and isomeric pyrano[3,2-b]azepines (3) were isolated by the application of trimethylsilyl azide or sodium azide in a methylene chloride or a chloroform solution in the presence of sulfuric acid At low temperature products (2) were almost sole products, while at higher
已经研究了 5,6,7,8-四氢-2H-1-苯并吡喃-2-酮 (1) 的施密特反应。吡喃并[3,2-c]氮杂 (2) 和异构体吡喃并[3,2-b]氮杂 (3) 的衍生物通过在二氯甲烷或氯仿溶液中应用三甲基甲硅烷基叠氮化物或叠氮化钠在存在的情况下进行分离硫酸在低温下的产物 (2) 几乎是唯一的产物,而在高温下的衍生物 (3) 也以合理的收率被分离出来。吡喃并[3,2-c]吡啶(5)的衍生物可以使用相同的方法由环戊-[b]吡喃-2,5-二酮(4)制备。